A group of First Nations plans to launch a slew of legal challenges against the federal government over its approval of the Petronas liquefied natural gas (LNG) project near Prince Rupert, BC.

Calling Justin Trudeau "an outright liar," Donnie Wesley, the highest ranking hereditary chief of Gitwilgyoots tribe, which has jurisdiction over Lelu Island where the LNG terminal would be built, said the project's approval on Tuesdaywas "a slap in the face."

Wesley told VICE News the federal decision "totally ignored" peer-reviewed, independent science submitted to the Canadian Environmental Assessment Agency that showed the project would seriously harm the salmon in the Skeena River, the second-largest salmon bearing river in BC, and a significant body of water for First Nations along the river.

"We don't have a tentative date, but it will be within the 30-day [appeal] period," Wesley said of his tribe's legal action. "We're going to be meeting next week to plan our strategies [and] where we're going to go with this."

Wesley's tribe, along with other First Nation groups and west coast non-profit SkeenaWild, have met with lawyers and are fundraising to apply for judicial review of the decision.

A GoFundMe campaign launched yesterday in support of their legal challenge has raised $3,000 in 19 hours—but Greg Knox, executive director of SkeenaWild, says his group has already raised about $50,000 toward its legal fund, with more fundraising events planned.

"Aboriginal groups and SkeenaWild have been preparing to launch a series of legal actions, and are prepared to go all the way," the fundraiser states.

"The Skeena Corridor Nations, a powerful group of hereditary leaders from Gitanyow, Lax Kw'alaams, Wet'suwet'en, Gitxsan, Takla, Lake Babine and Haida, are exploring all political and legal options for protecting the Skeena for the long-term."

"We've been preparing for the last year," Knox said. "Our lawyers are currently preparing to file for judicial reviews."

There will be multiple legal actions, he said, ranging from First Nations appeals over lack of consultation to judicial reviews of the CEAA report that found the project "is likely to cause significant adverse environmental effects." The government concluded those adverse effects "are justified in the circumstances," and applied 190 conditions to allow the project to go forward.

Read more: Everything You Need to Know About the $36-billion LNG Project That is Turning Many First Nations Against Trudeau

Knox said 130 of the world's leading salmon scientists found the salmon habitat along the Skeena River would be seriously harmed, but he says the report ignored that evidence.

"We believe that the report is fundamentally flawed in its findings, and that's what we're going to be showing in court."

Following mass job loss in the west due to the world oil downturn, the federal government has been under pressure from the Conservative opposition and the oil sector to approve energy projects. This project will add thousands of construction jobs and hundreds of operating and spin-off jobs in BC, and Petronas has said it would add $1.3 billion annually in taxes and royalties.

"I am confident with the 190 legally binding and scientifically-determined conditions that we will address the most important environmental impacts to ensure this project proceeds in the most sustainable manner possible," environment and climate change minister Catherine McKenna said as she announced the project's approval.

But the project has been stalled three years already as it jumped through regulatory hoops, and in that time, the price of LNG has dropped due to oversupply worldwide. Petronas says it is now reviewing the project to determine whether it is still economically viable. The review is expected to take months.

In last year's election, Prime Minister Justin Trudeau ran on promises to consult with First Nations on energy projects, return to a nation-to-nation relationship, and honour the UN's Declaration of the Rights of Indigenous Peoples, which states "Indigenous Peoples have the rights to the lands, territories and resources which they have traditionally owned, occupied or otherwise used or acquired."

"There's a lot of pressure on Prime Minister Trudeau to get something off the ground of substance, but he went against the grain of what he said, [he's] an outright liar," Wesley said.

"He's not holding up to what he's preaching to the world about holding the reconciliation with First Nations people. That's far from the truth. He's just taking up the old guard from Stephen Harper."

Asked for comment on Wesley's words and the forthcoming legal action, the Prime Minister's Office referred VICE News to a statement by the Prime Minister in question period on Wednesday:

"Mr. Speaker, we have always understood that in order to create the kind of government that people want, we need to both grow the economy and protect the environment," he said. "That means folding in consultations with Indigenous leaders, talking to communities, ensuring we get the world-class science done. That is exactly what we did on this project."